A lab meter is an instrument that measures one or more parameters or properties of a substance or an environment. Some lab meters measure the flow of air, gas, or water. An anemometer, for example, measures the velocity of air outdoors or within air ducts. Other lab meters measure environmental properties, such as air pressure or light. Still others are used for testing aqueous solutions to find the concentration of a particular substance in the solution or to measure conductivity, turbidity, viscosity, or other properties. For example, a pH meter can determine whether a substance is acidic, neutral, or alkaline. A meter used in a manufacturing setting may be referred to as an industrial meter.